Form-raising jack



A. P. W'IERTZ Feb. 13, 1945.

FORM-KAI S ING JACK 2 Sheets-Sheet 1 Filed June 3, 1943 Feb. 13, 1945.

A. P. wiERTz 2,369,195:

FORM-RAISING JACK Filed June 3, 1943 2 Sheets-Sheet 2 Patented Feb 13; 1945,

UNITED STATES PATENT OFFICE FORM-RAISING JACK I I 7 Anthony P. Wiertz, Dayton, Ohio 7 v Application June 3, 1943, Serial No. 489,520

Claims. (01. 254-120) The invention relatesto a jack mecha'nismprimarily adapted for use in raising concrete forms.

It is particularly aimed to provide a novel construction to coact with a rod upon which it may be operated toclimb, which rod functions also as a reinforcement for poured concrete.

In addition it is aimed to provide a novel means which will prevent slippage of the mechanism downwardly on the rod mentioned, and a construction wherein the yoke or biting parts are maintained under tension in order to bite or di rectly engage the rod at all times.

The more specific objects and advantages will become apparent from a consideration of the description following taken in connection with accompanying I drawings illustrating an operative embodiment.

In said drawings: a

Figure 1 is a view illustrating my improvement in elevation and in connection with a concrete form partly shown in elevation and partly in section;

Figure 2 is a view in elevation of my improvement taken at a right angle to Figure 1;

Figure 3 is a view in elevation of my improvement alone, looking in the samedirection as Figure 1, but partly broken away; Figure 4 is a view of my improvement taken at a right angle to Figure 3, and with most parts in substantially central longitudinal section; and

Figure 5 is a plan view of one of the yokes.

Referring specifically to the drawings wherein like reference characters designate like or similar parts, I employ a mount generally designated I0, having a basal flange at II and a hollow frustal conical portion I2 whose larger dimension is lowermost.

The base flange II is adapted'to be fastened in a horizontal plane in any suitable manner to a concrete form I3, for instance, which is adapted to be lifted through the operation of my improved jacking mechanism. The'form I3 employs one or more parts I4, in or between which the concrete is adapted to be poured, and'in or between which a rod I5 is vertically disposed, for the improved jacking mechanism to climb on, in order to raise the form. At the same time, it is to be understood that the jacking mechanism is capable of more general use and that its employment in connection withconcrete form structures is but one illustration of its use.

It will be noted that the rod I5 extends upwardly and centrally through the frustal portion I2. An operating lever having a part I6 generally of U shape is pivotally mounted, by suitable bolt means or trunnions I I on the conical part I2 and'from which a suitable handle I8projects.

.A pair of yokes -I9- are disposed at opposite angles, and the rod I5 passes through the same. Said yokes have vertical link 20 disposed on opposite sides of the rod with their upper ends at '2 I, pivotally connected to the yokes I9; and their lower ends 22 pivotally-connected to the operate ing lever at the U-shaped-portion I6. Thus it will beseen that the operation of the 'lever I6I 8 willresult in the jacks climbing or progressively ascending along the rod I5 and carrying with it the form I3 and all parts attached to it, permitting use of the form I3 at different elevations, as the pouring of concrete into or'between the part or'parts I4 progresses. e

In lieu of the yokes I9 directly engaging or biting the rod I5at an edge thereof, biting lugs 23 are provided on the yokes for direct biting action for'engagement with the rod. Said lugs or bars 23 preferably are ofrelatively hard metal and are removable and replaceable, simply being held in place by driving them into and out of openings of approximately theirown shape and size in the yokes. This type of mounting also enables the lugs 23 to be-driven by a hammer into different positions of adjustment to provide an eiTective biting edge when they become worn.

In addition, such lugs may be of any desired cross-sectional area, preferably, being polygonal as shown, so that they may be removed, and any of the plurality of edges shown be brought into position to engage the rod.

To enhance thebiting efiect and to maintain the lugs in engagement with the rod, contractile coil springs are employed at 24 across the joint or knuckle of the yokes I9 and links 20, being detachably connected to hooks 25 and 26, on such parts, respectively.

I also provide a safety means to prevent downward slippage or displacement of the jacking mechanism on the rod I5, which may consist of two or more slips or wedges 21, the same being separable from each other and collectively of the same shape as the space between the inner wall of the frustal portion I2 and outer wall of the rod I5. Said slips 2! are held in place and urged upwardly .by spring fingers at 28, fastened at 29 to the under surface of the basal flange II. It will be realized that'the wedges or slips 21 do not interfere with the raising of the jack and form on the rod I5 through operation of the lever .66 of downward slippage, the slips or wedges 21 will wedge between the part l2 and rod in order to hold the form and jacking mechanism in place.

Attention is called to the fact that the rod I5 remains permanently in the poured concrete to function dually as a reinforcement therefor as well as a means on which the jack climbs.

Various changes may be resorted to provided that they fall within the spirit and scope of the invention. v

I claim as my invention: 1. Jack mechanism of the classdescribed comprising .a :mount' "for iattachment ito a :part to be lifted, said mount being open so that a rod may extend through and above the same, lever means;

pivoted on the mount, and oppositely operable yokes disposed to bite the rodat opposite sides through the manipulation of the lever to lcause the jack to climb the rod, and wedge means retained by the mount to wedge'lbetween'ithexsame and the rod to avoid lowering of the mountlonthe rod. I

I .2; alackmecha'nismcof the ;class described roomprising razmount Ltor zatta'ohment to 1a part to Joe lifted, :said mount being :open :so that 23111011 may extend through-andabove athezsame, lever means pivoted on "the Imount, and moppositely operable yokes disposed :to "bite i the zrod at :opposite sides throughdshe manipulation ofathe'ieverutorcau-se the Jack {to climb the irod,--;andm.edge:means :retained by the mount -to' wedge' between :the same and VtheJIid tmaVOid lowering of 'themountonathe rod,

said xwedge 'means *ZEOIlSiSiliIl-Q Of a :;plurality .iof wedgewhapedcparts, thexmount having azconical extendithroughfiandmbovefthe;:same,zlever-means pivoted on the @mount, Rand r-oppositely :operable yokes disposed to bite the rod at oppositesides through the manipulation of the lever to cause the jack to climbthe rod, andwedge means retained by the mount to wedge between the same and the rod to avoid lowering of the mount on the rod, said wedge means consisting of a plurality of wedge-shaped parts; the mount having a conical portion in which the wedge-shaped parts are disposed, and spring means on the mount to retain said wedge members thereon, said'yoke members havingadjustablelbiting .elements to engage the-rodjlinfks pivoted'togthe leuerand to the I yokes, and contractile coil springs connected-to the yokes and the links urging said elements to biting engagement with the rod.

4. Jack mechanism of the class described comprising a mount for attachment to a part'to be '1ifted,'sa'id mount being open so that a rod may .throug'hand above the same, lever means pivoted on the mount, and oppositely operable yokes "disposed to bite the rod at opposite sides .throughfthelmanipulatiomoi the lever to causeathe jack to :olimb the zrod; said yokess-having adjust- .able biting elements providing aplurality of zedges forrselectiveiengagement with therod. :5. Jack-meehanismbfztheclassLd soribedlcom prising a mount for attachment "to a part .to he lifted, saidnmolintabeing-lopen so thatfip od m y .e-xtend through-and :above :the. same,slever means pivoted pen the ,mount, and -oppositely operable ,yokes disposed to bite the rod atroppositeisides through the manipulation (of the lever -;to ioau se the jack to climb the'rod, .said yokeshav-ingiadjustable biting elementsgprovi-din-g =at;-plurality of edges f or tselective engagementi withrthe rod, links p m a ly connected to; theyokes-andzto' the lever, andcontractilecoil ,springs fastened to thettokes and links to maintain the velements in'gengaga ment with the rod. I H t Pl LWIERZIZ. 

